In the field of high-frequency or microwave electronics, it is generally known to use waveguides rather than wired or galvanic connections for the transmission of signals between different elements, components, and assemblies. The waveguides are typically realized by tube- or channel-like elongated hollow structures with metallic sidewalls. The waveguides may, e. g. be of circular, square or rectangular cross section and may be optionally be ridged, e. g. single-ridged or double-ridged. Alternatively the waveguides may be realized in printed circuit board technology typically as substrate integrated waveguides. Alternatively, planar PCB transmission lines, e.g. microstrip, strip or coplanar waveguide lines, can be used.
An application where signals between different assemblies may be transmitted via waveguides to which reference is made in the following is the operative coupling between an electronic component, such as a microwave semiconductor component or a printed circuit board (PCB), and an antenna.